The police is the institution in charge of protecting public order and repressing crime, and it is entitled to use physical force in order to meet these functions. Police institutions are the product of a long-term historical trend toward differentiation and specialization. Before the beginning of the 19th century, differentiation as a contemporary function of policing (e.g., keeping peace and combating crime and disorder) was in the hands of watchmen appointed from households or by family or tribal constables. This “private” policing occurred in several areas (e.g., China, main parts of Africa, and South America) before the Europeled colonization process. Autonomous, professional, permanent—and in most cases local—police forces arose in the wake of urban growth and urban disorders, industrial disputes and riots, and crime fears. This institutionalization process accompanies a specialization process in the countries of continental Europe, where police imposed an ensemble of norms, …